Hand block for abrasives, etc.



. Nov. 17, 1925.

, LSGZAM- W. L. MCKNIGHT HAND BLOCK FOR ABHASI File d nomglgbleza ill! * Hiiiiiiiiiii Patented Nov. 17, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM LESTER MoKNIGI-IT, OF ST. PAUL, MINNESOTA, AS SI GNOR TO MINNESOTA MINING AND MANUFACTURING COMPANY; OF ST. PAUL, MINNESOTA, A GOR- PORATION OF MINNESOTA.

HAND BLOCK iron ABRASIVES, ETC.

Application filed November 14, 1922. Serial No. 600,831.

To all whom it may concern 7 Be it known, that I, WILLIAM LESTER MoKNIGH'r, a citizen of the United States, and aresident of St. Paul, in the county ,of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Hand Blocks for Abrasives, Etc,

of which the following is a specification.

This invention relates broadly to support- 10 ing and sustaining means, more particularly to an improved hand block for supporting and sustaining a sheet of abrasive material or the like, and especially one characterized by the feature of retaining such sheet by J the pressure ofthe hand grasping the block and for tensioning the sheet relatively to the block when in use, together 'with certain other features to be pointed out hereinafter.

While this invention, forthe sake of convenience, is illustrated as embodying a hand block adapted for carrying an abrasive sheet or for otherwise having an abrasive element associated therewith, it will be readily understood that the block as illustrated may be employed for other similar purposes, or may be embodied in combination with othermechanism as will occur to those skilled in the art, and therefore this inven- I tion finds a wide field of utility for other purposes than the specific ones herein discussed. v The principal objects and advantages which characterize this invention reside in the provision of improved means for carrying and sustaining an abrasive element; the

1 provision of improved flexible means for carryin and sustaining an abrasive element; t e provision of improved means for carrying and sustaining a sheet of abrasive material; the provision of improved flexible means for carrying and sustaining a sheet of abrasive material or the like; the provision of an improved hand block for carrying and sustaining a sheet of abrasive material or, the like, or one adapted for havin an abrasive element otherwise applie thereto; the provision of a compressible and flexible hand block, for carrying and sustaining a sheet of abrasive material, or the like, 'or one adapted for having van abrasive element otherwise appliedtheretq;

. the provision of an improved hand block; for carrying a sheet of abrasive material or the block like and characterized by the features of proper weight, flexibility, if desired, and

shape rendering it convenient to be grasped for use; the provision'of an improved hand block for carrying and sustaining a sheet the provision of an improved hand block for sustalning a sheet of abrasive material or the like, characterized by the provision of hand-pressure actuated sheet engaging means; the provision of an improvedhand block for sustaining a sheet of abrasive material or the like, characterized by the provision of means for tensioning the sheet relatively to the block by the application of manual pressure to the latter; the provision of an improved hand block characterized by the embodiment integrally therewith ,of hand-pressure actuated sheet engaging means; the provision of an improved hand block for sustaining a sheet of abrasive material or the like, characterized by the embodiment therein of hand-pressure actuated sheet engaging means and further characterized by feature of flexibility; the provision of an improved hand block for sustainin the like liaving means for tensioning the sheet relatively to the block by the application of manual pressure to the latter, such being further characterized, if desired, by the feature of flexibility; the provision of an article of the character described that is highly efiicient in operation, permits the user to manipulate the sheet of abrasive material withoutbringing his hands in contact with the surface being treated, or with the abrasive material, and which article may be manufactured at low ,cost; togetherv with certain further objects a sheet of abrasive material or and advantages which will hereinafter be pointed out or appear. 1 V This invention is further characterized by the provision of a structure which may be produced in one of several ways, and, therefore, .as this description proceeds, will embody thereinbrief references to certain alternate preferred methods for making thedevice of thisinvention. 1

The foregoing and such other objectsand advantages which mayappearror. Joe-pointed out as this description proceeds are attained in a structural embodiment illustrated in the accompanying drawing, in which:

Figure 1 is a perspective view of the device of this invention ready for use;

Figure 2 is a horizontal sectional view of the device of Figure 1 taken on a horizontal plane indicated by the dotted line A;

Figure 3 is a side elevation of the device of this invention illustrating the manner of applying a sheet of abrasive material or thelike thereto; and

Figure his a side elevational View illustrating one of the functions carried out by this invention.

Referring more particularly to the drawings, and first to Figures 1 and 2, I provide a block 5 preferably substantially rectangular in contour and having the plain surfaces 6 and 7, which, for convenience, I shall refer to as the bottom and top surfaces. The end faces 8 and 9 of the block are conveniently perpendicular with respectto the surfaces 6 and 7 and the sides 10 and 11 are similarly conveniently perpendicular to the top and bottom surfaces.

In the form of the invention shown in Figure 1 the body of material for forming the block 5 may be of rubber or any other flexible material, although if desired, the block may be made of a compressible or even of a rigid material. However, I shall, in describing the block, assume that the same is made of rubber, preferably a relatively stiff rubber yet sufliciently flexible for the purpose.

The block o includes the means for gripping the end portions 12 and 13 of an abrasive sheet 14, said sheet being engaged against the supporting surface 6 and such gripping means preferably comprising sinuated slots or recesses .15 and 16 cut or otherwise formed in the ends of the block and I disposed generally in planes above the horizontal longitudinal axes of the block so that resilient tongues 17 and 18 are afforded. The

slots 15 and 16 extend from the opposite end walls 8 and 9 toward the center of the block but terminate a sufiicient distance from each other so as not to materially weaken the construction.

It will be .observed here that informing the slots 12 and 13 they may be formed by sawing, the cut thus made by a saw being entirely sufiiciently large to accommodate a piece of sand paper or the like.

The following method, however, may be employed in making the device shown in Figure 1 and also emp oyed where it is desired to make the body 5 carrying the surface 6 of hard rubber and the upper portion of the block of soft rubber so as to afford the flexible tongues 17 and 18 (or conversely) that is to say, the bottom section 5- is molded to afford the sinuated surfaces 19 and 20 shown in Figure 2, and these surfaces may include transverse and longitudinal corrugations 2L and 22, respectively. The upper section of the block carrying the tongues 17 and 18 is then molded and provided with complemental surfaces to those designated 19 and 20. The upper section is then placed upon the lower section and the two either vulcanized or cemented to gether along the dotted line A.

By this arrangement it will be observed that the lower section of the block may be made of hard rubber and the upper section of soft rubber, or vice-versa, or both sections may be made of rubber of the same consistency. Furthermore, the degree of flexibility of the material of which .the block is formed, rubber or any other suitable material, may be' varied to suit the requirements of the use to which the article is to be put.

Another feature which is worthy of mention here is that especially when applied to a machine, for which the invention finds utility, the sections of the block formed by It is to be observed that when the oper-.

ator grasps the block the corrugated surfaces of the slots 12 and 13 serve to firmly engage the ends of the sheet interposed therebetween and by compression tend to shorten thesheet and thus tension its portion 14 on the surface 6. This will especial ly' take place where a very thin sand or emery paper is used and in actual practice has been found to possess a high degree of efliciency and utility.

'Upon reference to Figure 4 it will be perceived that where the abrasive material is employed polishing a eurved surface 23, the block may be caused to flex and take the form of the surface to which it is applied and thus insure that an accurate and smooth application of the abrasive material is attained.

The view shown in Figure 3 serves to illustrate the manner of applying the abrasive sheet to the block, this being accomplished by placing the block on the sheet and lifting the end tongues 17 and 18 a sufficient distance to permit insertion of the ends 12 and 13 of the sheet. When the ends of the sheet are inserted the tongues are released and returned to the position shown in Fi re 1.

Having thus described by invention and illustrated its use, what I claim as new 2. In a device of the character described, in combination, a flexible block having sinuated recesses in its ends, and an abrasive element embracing one surface of the block and engaged in said recessed ends.

3. In a device of the character described, in combination, a solid flexible body having flexible tongues spaced therefrom, and the portions of said body adjacent said tongues being corrugated.

4. In a device of the character described, in combination, a solid flexible body having flexible tongues spaced therefrom, and the surfaces of said body adjacent said tongues, and said tongues being corrugated.

5. In combination, a flexible body havin flexible tongues spaced therefrom, said body being provided with transversely and longitudinally corrugated surfaces adjacent to said tongues, and a flexible abrasive sheet having its ends between said tongues and said corrugated surfaces.

6. A supporting. and retaining device for abrasives and the like which includes a continuous flexible block provided with recesses in opposite. ends thereof, the complemental portions of the block formed by to impinge upon and retain a sheet of material on the block when pressure is applied thereto. 7. A supporting and retaining device for abrasives and the like which comprises a continuous flexible block provided with recesses in opposite ends thereof, abrasive sheet having its ends in said recesses the flexibility ofthe material of said block when pressure is applied thereto causing the parts of the block adjacent said recess to frictionally engage and retain said sheet upon the block.

8. In a device of the character described, a hand block for sustaining a sheet of abrasive material, having an integral part thereof formed as means for engaging said sheet, said means being actuated by the pressure of the hand to increase the securement of the sheet on said block, said means being rendered substantially inactive and permitting removal of the sheet upon release of the pressure of the hand.

TH testimony whereof I have hereunt signed my name.

WILLIAM LESTER McKNlGl'lT. 

